Dear students,

we have moved the processor boards and motors to the computer laboratory KN:E-2. The hardware remains there until the first seminaries in 2017.

The room KN:E-2 at Karlovo namesti is accessible to students without supervisor. If it is locket, ask gatekeeper politely to open it for you. The key for storage locker is available from the gatekeeper as well.

Shared memory on PowerPC MIDAM boards

Some students designed semestral work as separated motion controller and monitoring application running in separated address spaces- The control part designed as Kernel Loadable Module and TCP communication as separated Real Time Process. That is right approach for professional application for sure but we do not expect such architecture from you. The time is limited etc. Separated threads in a single Kernel Loadable Module are fully fulfilling our expectations.

But for these who has tried more secure and isolated solution, we have prepared VxWorks kernel image with shared memory support option enabled during build. It is not booted by default.

If you want to check this option then break boot process after the board reset. There is special delay and counting seen on the serial console. Press enter at that time. Then run/copy paste next commands line by line (some delay between lines may be required)

dhcp mw f0000b00 ${psc_cfg} tftp 0x100000 vxworks/vxWorks-midam-shm.bin-6.9 go 0x100000

You have to select alternative/corresponding kernel image file with symbols when you create target connection

/opt/psr/vxWorks-midam-shm-6.9

Then you can create shared memory regions, mesage-queues and POSIX threads.

I suggest these experiments only to these students who are ahead of time with their project and have interest to learn and experiment more than is goal and purpose of the subject. We are happy to support such people.

I have done some but minimal testing of the image. I have only checked that semOpen, shm_open and mmap links OK and does not throw error in the both, RTP and KLM. It is possible that there is some unnoticed problem and I do not have time to correct such problem now. So option is available for brave souls with time reserve for backup solution and without guarantee of any kind. If you use this option successfully or notice show stopper problem, it would be nice if you send info to the PSR list.

I wish you to enjoy your work, spent holidays hapilly and keep strong health now and in the future,

Pavel Pisa